diff --git a/lib/admin/list.ts b/lib/admin/list.ts
index 1398aa7..34d1f05 100644
--- a/lib/admin/list.ts
+++ b/lib/admin/list.ts
@@ -1,6 +1,6 @@
 import type { User } from '@supabase/supabase-js';
 import { getSupabaseAdmin } from '@/lib/supabase/admin';
-import { withAdminRetry, mapWithConcurrency } from '@/lib/admin/retry';
+import { withAdminRetry } from '@/lib/admin/retry';
 import {
   parseOrder,
   parseSort,
@@ -77,16 +77,6 @@ type TunnelRow = TunnelJoinRow & {
 const USER_SCAN_MAX_PAGES = 50;
 const USER_SCAN_PER_PAGE = 1000;
 
-// Resolve tunnel owner emails a couple at a time rather than all at once. The
-// upstream tolerates a small concurrent burst, but a large fan-out of
-// getUserById calls (one per row, all in flight) trips an upstream throttle that
-// truncates the tail of the burst into empty/partial bodies. Those truncations
-// arrive faster than the per-call retry window can clear them, so a few rows
-// were deterministically rendered as "—" on every list load. A low concurrency
-// keeps each lookup inside the throttle allowance; measured 0 failures at 2 and
-// consistent truncations at 4, so we stay conservative here.
-const OWNER_EMAIL_CONCURRENCY = 2;
-
 function userSortValue(u: User, sort: UserSort): string | number {
   switch (sort) {
     case 'email':
@@ -299,26 +289,34 @@ export async function getTunnelsList(opts: {
     total = count ?? rows.length;
   }
 
-  // Resolve owner emails (per-row getUserById; acceptable for current scale).
-  // The user_id comes from an existing tunnel row, so an empty body here is a
-  // transient burst flake rather than a genuine not-found — retry it, and bound
-  // the concurrency so the enrichment doesn't self-throttle. The try/catch null
-  // fallback remains as a last resort so one bad row can never 500 the whole
-  // list (it surfaces as "—" only if every retry still fails).
-  const emails = await mapWithConcurrency(
-    rows,
-    OWNER_EMAIL_CONCURRENCY,
-    async (t) => {
-      try {
-        const { data: u } = await withAdminRetry(() =>
-          admin.auth.admin.getUserById(t.user_id),
-        );
-        return u.user?.email ?? null;
-      } catch {
-        return null;
+  // Resolve owner emails via a single bounded listUsers scan rather than one
+  // getUserById per row. The upstream admin gateway deterministically truncates
+  // the first per-row lookup that immediately follows the request's auth check
+  // (an empty body the per-call retry can't clear), which surfaced as "—" on
+  // every load. A single listUsers read does not hit that pattern, so we scan
+  // the directory once (bounded, with the same transient-retry) and build an
+  // id→email map, stopping as soon as every owner on this page is resolved.
+  const wanted = new Set(rows.map((t) => t.user_id));
+  const emailById = new Map<string, string | null>();
+  if (wanted.size > 0) {
+    for (let p = 1; p <= USER_SCAN_MAX_PAGES; p++) {
+      const { data, error } = await withAdminRetry(() =>
+        admin.auth.admin.listUsers({ page: p, perPage: USER_SCAN_PER_PAGE }),
+      );
+      if (error) throw new Error(error.message);
+      const us = data.users;
+      if (us.length === 0) break;
+      for (const u of us) {
+        if (wanted.has(u.id)) emailById.set(u.id, u.email ?? null);
       }
-    },
-  );
+      // Stop early once every owner on this tunnels page has been found.
+      if (rows.every((t) => emailById.has(t.user_id))) break;
+      if (us.length < USER_SCAN_PER_PAGE) break;
+    }
+  }
+  // Any owner not found in the scan falls back to "—" (null) — graceful, and a
+  // missing owner can never 500 the whole list.
+  const emails = rows.map((t) => emailById.get(t.user_id) ?? null);
 
   const tunnels: TunnelItem[] = rows.map((t, i) => ({
     user_id: t.user_id,
diff --git a/lib/admin/retry.ts b/lib/admin/retry.ts
index 2abf939..9c75f60 100644
--- a/lib/admin/retry.ts
+++ b/lib/admin/retry.ts
@@ -126,33 +126,3 @@ export async function withAdminRetry<R extends { error: MaybeError }>(
   if (threw) throw lastThrown;
   return lastResult as R;
 }
-
-/**
- * Map over `items` running at most `concurrency` async tasks at a time, while
- * preserving result order.
- *
- * Firing every GoTrue admin lookup at once (e.g. one `getUserById` per tunnel
- * row) can self-inflict an upstream throttle: the proxy truncates the tail of a
- * large concurrent burst, producing the very empty-body responses we retry on —
- * and because the retries fire back into the same saturated window, a few rows
- * can still fail. Bounding the concurrency keeps each lookup inside the
- * throttle's allowance so {@link withAdminRetry} reliably resolves every row.
- */
-export async function mapWithConcurrency<T, R>(
-  items: readonly T[],
-  concurrency: number,
-  task: (item: T, index: number) => Promise<R>,
-): Promise<R[]> {
-  const results = new Array<R>(items.length);
-  const limit = Math.max(1, Math.min(concurrency, items.length || 1));
-  let next = 0;
-  async function worker(): Promise<void> {
-    for (;;) {
-      const i = next++;
-      if (i >= items.length) return;
-      results[i] = await task(items[i], i);
-    }
-  }
-  await Promise.all(Array.from({ length: limit }, () => worker()));
-  return results;
-}